System and method for heating a fuel using a solar heating system

ABSTRACT

An embodiment of the present invention may take the form of a system and method that may use at least one solar heating system to heat the fuel consumed by a turbomachine. An embodiment of the present invention may incorporate concentrated solar power (CSP). Generally, CSP systems incorporate a plurality of lenses, mirrors, or combinations thereof and a tracking system to focus a large area of sunlight forming a small concentrated beam of light. The concentrated light may then be used as a heat source. In an embodiment of the present invention, the heat source may be used to partially or completely heat the fuel consumed by a turbomachine. CSP systems may take the form of a solar trough system, a parabolic dish system, a solar power tower system, or the like.

BACKGROUND OF THE INVENTION

The present invention relates to the fuel consumed by a turbomachineduring operation; and more particularly to a system and method ofutilizing a solar heating system to heat the fuel consumed by theturbomachine.

The temperature of the fuel consumed by a turbomachine is generallyrequired to be within a specific range. The fuel may include, but is notlimited to, various type of fuel oil, a natural gas, or a synthetic gas.The combustion systems of some turbomachines require a ‘heated’ fuelsuch as, heated natural gas. Generally, the natural gas supply does notheat the natural gas to the required temperature of the turbomachine.Here, a fuel heater is used to increase the temperature of the naturalgas to meet the turbomachine requirements. The fuel heater requires anenergy source to operate. Some fuel heaters require that the energysource provide between 5 and 7 megawatts of power. Typically, the energysource derives from the turbomachine, such as, but not limiting of, agenerator coupled to the turbomachine, heated water from a heat recoverysteam generator, or the like.

Solar power is a renewable energy source whose application and usage ison the rise. Solar power usage can be advantageous in regions whereturbomachines are exposed to a sufficient amount of sunlight. Some ofthe benefits of using solar power include, but are not limited to:increase in the output and efficiency of the turbomachine and areduction in turbomachine emissions.

The efficiency of solar power systems varies on the type of solartechnology used. This variance can make the addition of solar technologyto a turbomachine site cost prohibitive.

For the foregoing reasons, there is a need for a system that reduces theparasitic load associated with heating the fuel consumed by aturbomachine. The system should incorporate a relatively efficient solartechnology to increase the temperature of the fuel consumed by theturbomachine.

BRIEF DESCRIPTION OF THE INVENTION

In accordance with an embodiment of the present invention, a system forincreasing a temperature of a fuel, the system comprising: a system forincreasing a temperature of a fuel, the system comprising: aturbomachine comprising a combustion system for combusting a fuel; andat least one solar heating system configured for heating the fuel,wherein the solar device is integrated with a fuel supply system locatedupstream of the combustion system; wherein the at least one solarheating system heats the fuel from a first temperature to a secondtemperature.

In accordance with an alternate embodiment of the present invention amethod of increasing a temperature of a fuel, the method comprising: amethod of increasing a temperature of a fuel, the method comprising:providing a turbomachine, wherein the turbomachine comprises acombustion system for combusting a fuel; providing at least one solarheating system configured for heating the fuel, wherein the at least onesolar heating system is integrated with a fuel supply system; andutilizing the at least one solar heating system to heat the fuel from afirst temperature to a second temperature.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustrating an environment in which an embodimentof the present invention may operate.

FIG. 2 is a schematic illustrating an example of a solar heating systemin accordance with an embodiment of the present invention.

FIG. 3 is a schematic illustrating an example of a solar heating systemin accordance with an alternate embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description of preferred embodiments refers tothe accompanying drawings, which illustrate specific embodiments of theinvention. Other embodiments having different structures and operationsdo not depart from the scope of the present invention.

Certain terminology is used herein for the convenience of the readeronly and is not to be taken as a limitation on the scope of theinvention. For example, words such as “upper,” “lower,” “left,” “right,”“front”, “rear” “top”, “bottom”, “horizontal,” “vertical,” “upstream,”“downstream,” “fore”, “aft”, and the like; merely describe theconfiguration shown in the Figures. Indeed, the element or elements ofan embodiment of the present invention may be oriented in any directionand the terminology, therefore, should be understood as encompassingsuch variations unless specified otherwise.

The present invention may be applied to the variety of turbomachinesthat produce a gaseous fluid, such as, but not limiting of, a heavy-dutygas turbine; an aero-derivative gas turbine; or the like. An embodimentof the present invention may be applied to either a single turbomachineor a plurality of turbomachines. An embodiment of the present inventionmay be applied to a turbomachine operating in a simple cycle or acombined cycle configuration.

An embodiment of the present invention takes the form of a system andmethod that may use at least at least one solar heating system to heatthe fuel consumed by a turbomachine. The elements of the presentinvention may be fabricated of any material that can withstand theoperating environment under which the solar heating system may functionand operate.

An embodiment of the present invention may incorporate concentratedsolar power (CSP). Generally, CSP systems incorporate a plurality oflenses, mirrors, or combinations thereof and a tracking system to focusa large area of sunlight forming a small concentrated beam of light. Theconcentrated light may then be used as a heat source. In an embodimentof the present invention, the heat source may be used to partially orcompletely heat the fuel consumed by a turbomachine. CSP systems maytake the form of a solar trough system, a parabolic dish system, a solarpower tower system, or the like.

Referring now to the Figures, where the various numbers represent likeelements throughout the several views, FIG. 1 is a schematicillustrating an environment in which an embodiment of the presentinvention may operate. FIG. 1 illustrates a turbomachine 100 in acombined cycle configuration, and at least one solar heating system 175.The turbomachine 100 generally comprises a compressor 105, a combustionsystem 110, and a turbine section 115. A stack 140 may be locateddownstream of the turbine section 115.

Generally, the compressor 105 receives and compresses an inlet air,represented by an arrow in FIG. 1. The compressed air may flowdownstream to the combustion system 110, where the compressed air ismixed with a fuel 130, such as, but not limiting of, a natural gas, andthen combusted. The energy released during the combustion process flowsdownstream and drives the turbine section 115. A load, such as, but notlimiting of, a generator 125 may be coupled to the turbomachine 100,wherein the mechanical torque generated in the turbine section 115 maydrive the generator 125.

The exhaust 120 generated during the operation of the turbomachine 100may flow downstream towards a heat recovery steam generator (HRSG) 135.The HRSG 135 utilizes a heat exchanging process to transfer some of theheat in the exhaust 120 to a condensate 165, creating steam 145. Thesteam 145 may flow downstream to a steam turbine 150, which may becoupled to a load, such as, but not limiting of, a generator 155. Duringthe operation of the steam turbine 150, the steam 145 may condense in acondensor 160, forming a condensate 165. A pump 170, such as, but notlimiting of, a boiler feed pump, may drive the condensate 165 into theHRSG 135, where the aforementioned process may be repeated. Afterflowing through the HRSG 135, the exhaust 120 may flow through the stack140.

The turbomachine 100 receives the fuel 130 from a fuel supply system133. The fuel supply system 133 may begin where the fuel 130 is suppliedto the site; flow through a fuel compressor 180 and then to thecombustion system 110. As discussed, some turbomachines 100 required aheated fuel for performance and/or other reasons. Here a fuel gas heater185 may be positioned along the fuel supply system 133 to heat the fuel130 to the desired operating range. The fuel gas heater 185 typicallyconsumes roughly 2-8 megawatts of the energy produced by theturbomachine 100 if heated by IP water from the HRSG.

A first embodiment of the at least one solar heating system 175 maycomprise a parabolic trough system 200, as illustrated in FIGS. 1 and 2.An embodiment of the parabolic trough system 200 may comprise aplurality of linear parabolic reflectors 205 that concentrate thesunlight onto a receiver 210 positioned along a focal line of theparabolic reflectors 205. The linear parabolic reflectors 205 aredesigned to follow the sunlight during the daylight hours by trackingalong at least one axis (not illustrated in the figures). The receiver210 may comprise a pipe through which the fuel 130 may flow. Here, theat least one solar heating system 175 may heat the fuel 130 via aconvection form of heat transfer, such as, but not limiting of, forcedconvection, natural convection, or the like.

A second embodiment of the at least one solar heating system 175 maycomprise a solar tower system 300, as illustrated in FIG. 3. Anembodiment of the solar tower system 300 may incorporate a plurality oftracking reflectors 305 for concentrating sunlight light onto a centralreceiver 310 near the top of a tower 315. The receiver 310 may comprisea pipe through which the fuel 130 may flow. Here, the at least one solarheating system 175 may heat the fuel 130 via a convection form of heattransfer, such as, but not limiting of, forced convection, naturalconvection, or the like.

In use, the at least one solar heating system 175 may heat the fuel 130from a first temperature to a second temperature. Here, the firsttemperature may be considered the unheated temperature of the fuel 130.In an embodiment of the present invention, the first temperature may beup to about 150 degrees Fahrenheit. Furthermore, the second temperaturemay be considered the heated temperature of the fuel 130. In anembodiment of the present invention, the second temperature may be up toabout 700 degrees Fahrenheit.

The at least one solar heating system 175 may provide a user with aplurality of benefits. In an embodiment of the present invention the atleast one solar heating system 175 may provide up to about 8 megawattsof equivalent power generated by a typical heavy duty turbomachine. Inan embodiment of the present invention, the at least one solar heatingsystem 175 may have an efficiency of up to about 85%.

An alternate embodiment of the present invention may integrate the atleast one solar heating system 175 with an existing fuel gas heater 185.This embodiment may allow for continued heating of the fuel 130 when theat least one solar heating system 175 may be to available to provide allof the energy required to heat the fuel. For example, but not limitingof, during extending periods of less than ideal sunlight the at leastone solar heating system 175 and the fuel gas heater 185 may operatetogether to heat the fuel 130.

A second alternate embodiment involves using solar power to heat thecondensate 165 before entering the HRSG 135. This may allow for anincrease in the efficiency of the HRSG 135 by requiring less work toproduce steam. Here, the at least one solar heating system 175 used toheat the fuel 130 may be integrated with the condensate loop. This mayallow for the aforementioned at least one solar heating system 175 toheat the fuel 130 and the condensate 165.

Alternatively, a condensate heating system 190 may be integrated withthe condensate loop to heat the condensate 165. The condensate heatingsystem 190, may operate as an independent solar power system. Thecondensate heating system 190 may comprise the form and function of theat least one solar heating system 175, as previously described.

Alternatively, the fuel gas heater 185 may transfer excessive thermalenergy from solar to the condensate 165 to increase the generation ofsteam 145 when sunlight is sufficient. Here, the fuel gas heater 185 maybe function as fuel cooler.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

Although specific embodiments have been illustrated and describedherein, it should be appreciated that any arrangement, which iscalculated to achieve the same purpose, may be substituted for thespecific embodiments shown and that the invention has other applicationsin other environments. This application is intended to cover anyadaptations or variations of the present invention. The following claimsare in no way intended to limit the scope of the invention to thespecific embodiments described herein.

1. A system for increasing a temperature of a fuel, the systemcomprising: a turbomachine comprising a combustion system for combustinga fuel; and at least one solar heating system configured for heating thefuel, wherein the solar device is integrated with a fuel supply systemlocated upstream of the combustion system; wherein the at least onesolar heating system heats the fuel from a first temperature to a secondtemperature.
 2. The system of claim 1, wherein the at least one solarheating system is integrated with the fuel supply system and comprisesat least one of: a parabolic trough system, a solar tower system, orcombinations thereof.
 3. The system of claim 1, further comprising afuel gas heater for assisting the at least one solar heating system withheating the fuel.
 4. The system of claim 1, wherein the firsttemperature of the fuel is up to about 150 degrees Fahrenheit.
 5. Thesystem of claim 1, wherein the second temperature of the fuel is up toabout 700 degrees Fahrenheit.
 6. The system of claim 1 furthercomprising at least one condensate heating system for heating acondensate of a HRSG.
 7. The system of claim 6, wherein the at least onecondensate heating system comprises at least one of: a parabolic troughsystem, a solar tower system, or combinations thereof.
 8. The system ofclaim 1, wherein the at least one solar heating system heats the fueland heats a condensate of a HRSG.
 9. The system of claim 8, wherein theat least one solar heating system utilizes a convection system ofheating.
 10. The system of claim 1, wherein the at least one solarheating system provides up to about 8 megawatts of solar power.
 11. Thesystem of claim 1, wherein an efficiency of the at least one solarheating system is up to about 85% efficient.
 12. A method of increasinga temperature of a fuel, the method comprising: providing aturbomachine, wherein the turbomachine comprises a combustion system forcombusting a fuel; providing at least one solar heating systemconfigured for heating the fuel, wherein the at least one solar heatingsystem is integrated with a fuel supply system; and utilizing the atleast one solar heating system to heat the fuel from a first temperatureto a second temperature.
 13. The method of claim 12, wherein the atleast one solar heating system is integrated with the fuel supply systemand comprises at least one of: a parabolic trough system, a solar towersystem, or combinations thereof.
 14. The method of claim 12, furthercomprising providing a fuel gas heater for performing the step ofassisting the at least one solar heating system with heating the fuel.15. The method of claim 12, further comprising increasing the firsttemperature to up to about 150 degrees Fahrenheit.
 16. The method ofclaim 12, further comprising increasing the second temperature of thefuel to up to about 700 degrees.
 17. The method of claim 12, furthercomprising utilizing at least one condensate heating system to heat acondensate of a HRSG.
 18. The method of claim 17, wherein the at leastone condensate heating system comprises at least one of: a parabolictrough system, a solar tower system, or combinations thereof.
 19. Themethod of claim 12, wherein the at least one solar heating systemperforms the steps of heating the fuel and heating a condensate enteringa HRSG.
 20. The method of claim 12, wherein the at least one solarheating system performs the step of utilizing a convection system ofheating to increase a temperature of the fuel.